# Fluids & Particle Simulation vs RYUKIN

The clearest difference is price: Fluids & Particle Simulation at Free against RYUKIN's $3.49. Fluids & Particle Simulation also leads on ratings volume (770 vs 62) and device support (4 vs 2). RYUKIN's advantage is update cadence (weekly vs monthly). On rating, review sentiment, ads and in-app purchases there is nothing between them.

Fluids & Particle Simulation is free to download; RYUKIN costs $3.49 up front. Fluids & Particle Simulation sells 8 in-app purchases, starting at $2.99 per 7 days and RYUKIN sells 35 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

RYUKIN holds the better App Store score, 4.9 against 4.7. That said, the two scores are not equally well evidenced: Fluids & Particle Simulation has 770 ratings behind it against 62, so its average is the more settled of the two. Written reviews point the same way: 90% of Fluids & Particle Simulation's written reviews are positive against 94% of RYUKIN's.

Fluids & Particle Simulation ships an update monthly, RYUKIN weekly. The most recent releases landed on October 15, 2026 and October 18, 2026 respectively.

## The numbers

| Metric | Fluids & Particle Simulation | RYUKIN |
| --- | --- | --- |
| Price | **Free** | $3.49 |
| Rating | [4.7 (770 ratings)](https://appshunter.io/ios/app/fluids-and-particle-simulation/id1532653221/reviews) | **[4.9 (62 ratings)](https://appshunter.io/ios/app/ryukin/id6471839445/reviews)** |
| Number of ratings | **770** | 62 |
| Positive reviews | 89.6% of reviews | **94.0% of reviews** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Monthly | **Weekly** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 189 MB | 227 MB |
| Requires iOS | **13.0** | 16.0 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [ZipoApps](https://appshunter.io/developer/1671444635) | [Masataka Hakozaki](https://appshunter.io/developer/323346554) |

## What reviewers say

### Fluids & Particle Simulation

[App page](https://appshunter.io/ios/app/fluids-and-particle-simulation/id1532653221)

Create mesmerizing, psychedelic fluid art with your fingertips. This app offers a calming and creative outlet to reduce stress and channel negative emotions into beautiful, flowing patterns. Enjoy a unique ASMR experience with sound-reactive visuals and customizable parameters.

**Highlights:** Interactive fluid art simulation, Sound-reactive fluids, Dozens of customizable parameters, Autopilot mode, Gyrosensor and haptic feedback integration, Real-time sound synthesis, Video recording and screenshot functionality

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock all features | $2.99 | per 7 days |
| Unlock all \| monthly premium | $5.99 | per month |
| Fluids PRO | $17.99 | per year |
| Unlock all Presets (iOS) | $1.99 | one-time |
| Unlock all Presets (OS X Mac) | $2.99 | one-time |
| Unlock all features | $14.99 | one-time |
| Psychedelic magic (OS X Mac) | $24.99 | one-time |
| Psychedelic magic (iOS) | $44.99 | one-time |

**What reviewers like**

- 🚀 Mesmerizing visuals
- 👍 Relaxing and calming experience
- 🎨 Customizable color and fluid effects
- 🎶 Enjoyable audio/music integration
- 💡 Innovative and creative app concept

**What reviewers complain about**

- 🐛 Occasional crashes or bugs
- 🔋 Device overheating issues
- 💰 Paid features may be too expensive
- 🔇 Lack of volume/audio control options

**Reported bugs**

- Microphone input not working as expected
- Difficulty resetting or restoring default settings

**Requested features**

- Ability to sync visuals with external audio/music
- More preset options and visual effects
- Improved UI/UX for settings and controls
- Support for casting to external displays


### RYUKIN

[App page](https://appshunter.io/ios/app/ryukin/id6471839445)

Experience the serene beauty of goldfish swimming in a customizable virtual aquarium. Interact with the fish, adjust tank settings, and enjoy soothing visuals and sounds. Perfect for relaxation or a calming presence.

**Highlights:** Interactive goldfish that respond to touch, Customizable tank shape and background, Soothing water sounds and visuals, Cat & Baby Mode for safe interaction, Sleep timer for bedtime use, Play your own music, Clock and date display

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (35)**

| Purchase | Price | Billing |
| --- | --- | --- |
| WIREFRAME RAINBOW | $0.99 | one-time |
| ROBO FISH 02 | $1.99 | one-time |
| ROBO FISH 04 | $1.99 | one-time |
| ROBO FISH 06 | $1.99 | one-time |
| GHOST BRIDE | $1.99 | one-time |
| BAT FISH | $1.99 | one-time |
| CALICO ORANGE/WHITE/BLACK | $1.99 | one-time |
| BLACK WHITE KITTY FISH | $1.99 | one-time |
| GHOST TRANSLUCENT | $1.99 | one-time |
| BLACK KITTY FISH | $1.99 | one-time |
| WHITE KITTY FISH | $1.99 | one-time |
| ROBO FISH 03 | $1.99 | one-time |
| GHOST BLACK | $1.99 | one-time |
| ROBO FISH 01 | $1.99 | one-time |
| ORANGE & WHITE KITTY FISH | $1.99 | one-time |
| RED RYUKIN | $1.99 | one-time |
| RED-WHITE RYUKIN | $1.99 | one-time |
| CALICO RED/WHITE/BLACK | $1.99 | one-time |
| ORANGE/WHITE | $1.99 | one-time |
| CALICO RED/GRAY/BLACK | $1.99 | one-time |
| YELLOW GOLD RYUKIN | $1.99 | one-time |
| RED CAP ORANDA | $1.99 | one-time |
| RED/WHITE II | $1.99 | one-time |
| LIONHEAD ORANGE/WHITE/BLACK | $1.99 | one-time |
| GHOST LUMINOUS | $1.99 | one-time |
| BLACK RYUKIN | $1.99 | one-time |
| CALICO KITTY FISH | $1.99 | one-time |
| GRAY WHITE KITTY FISH | $1.99 | one-time |
| WHITE VAMPIRE | $1.99 | one-time |
| BLACK VAMPIRE | $1.99 | one-time |
| BLACK WITCH | $1.99 | one-time |
| WHITE WITCH | $1.99 | one-time |
| ZOMBIE FISH | $1.99 | one-time |
| SKELETON FISH | $1.99 | one-time |
| PANDA TELESCOPE | $1.99 | one-time |

**What reviewers like**

- 💎 Gorgeous and lifelike fish
- 🎨 Beautiful and customizable environments
- 🎶 Soothing water sounds
- 🕰️ Useful clock feature
- 👍 Immersive and relaxing experience

**What reviewers complain about**

- 🔋 High battery consumption on max settings
- 💰 Additional fish require paid purchases
- 🌱 Lack of plant/natural decor options
- 🐟 Limited variety of standard goldfish

**Reported bugs**

- Occasional crashing on high-end devices

**Requested features**

- Ability to change fish colors
- Add more fish species (e.g. bettas, tetras)
- Implement fish breeding/growth mode
- Allow customizing fish placement in tank
- Add desktop/widget mode for always-on display


## Frequently asked questions

### Is Fluids & Particle Simulation free?

Fluids & Particle Simulation is free to download, with in-app purchases available.

### Is RYUKIN free?

RYUKIN costs $3.49, and also offers in-app purchases.

### Which has better reviews, Fluids & Particle Simulation or RYUKIN?

RYUKIN is rated higher. Fluids & Particle Simulation averages 4.7 out of 5 from 770 ratings, while RYUKIN averages 4.9 from 62 ratings.

### Do Fluids & Particle Simulation or RYUKIN have ads?

Neither Fluids & Particle Simulation nor RYUKIN shows ads.

### Which is updated more often, Fluids & Particle Simulation or RYUKIN?

Fluids & Particle Simulation ships an update monthly, and RYUKIN weekly. Most recently, Fluids & Particle Simulation was updated on October 15, 2026 and RYUKIN on October 18, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*